In a modern automobile, a self-locking transmission or braking mechanism is often used to adjust various positions, for example, to adjust the height of a seat.
A conventional brake mechanism generally has a structure of a torsion spring type, mainly for the purpose of pressing against or releasing from a friction wall by adjusting the size of the diameter of the torsion spring. However, this has an obvious disadvantage that the torsion moment received is small. An adjusting device for an automobile seat is disclosed in CN Patent Application No. 22954716, the adjusting device is connected to four sets of link mechanisms through a sliding core and drives the four sets of link mechanisms to move through a two-stage gear transmission, such that a seat basin connected to the link mechanism may be moved upward and downward, therefore achieving height adjustment of the seat. In this way, however, the structure is complicated and the position of the seat is not secure, which results in that the basin is easy to be raised or lowered in an uncontrolled way when a passenger who seats on the basin wrenches the seat.